Performance of the Idylla microsatellite instability test in endometrial cancer

Context: DNA mismatch repair (MMR) deficiency (dMMR) testing is now recommended in endometrial cancer. Defect identification in the molecules participating in this pathway, or the presence of microsatellite instability, are commonly employed for this purpose. Novel methods are continuously evolving...

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Bibliographic Details
Authors: Mendiola, Marta, Heredia-Soto, Victoria, Ruz-Caracuel, Ignacio, Baillo, Amparo, Ramon-Patino, Jorge Luis, Berjon, Alberto, Escudero Ruiz, Francisco Javier, Peláez-García, Alberto, Hernandez, Alicia, Feliu, Jaime, Hardisson, David, Redondo, Andres
Format: article
Publication Date:2024
Country:España
Institution:Instituto de Salud Carlos III (ISCIII)
Repository:Repisalud
Language:English
OAI Identifier:oai:repisalud.isciii.es:20.500.12105/26370
Online Access:https://hdl.handle.net/20.500.12105/26370
Access Level:Open access
Keyword:Endometrial carcinoma
Idylla
Microsatellite instability
Mismatch repair deficiency
Adult
Aged
Biomarkers, Tumor
DNA Methylation
DNA Mismatch Repair
DNA-Binding Proteins
Endometrial Neoplasms
Female
Humans
Immunohistochemistry
Microsatellite Instability
Middle Aged
Mismatch Repair Endonuclease PMS2
MutL Protein Homolog 1
Sensitivity and Specificity
Description
Summary:Context: DNA mismatch repair (MMR) deficiency (dMMR) testing is now recommended in endometrial cancer. Defect identification in the molecules participating in this pathway, or the presence of microsatellite instability, are commonly employed for this purpose. Novel methods are continuously evolving to report dMMR/microsatellite instability and to easily perform routine diagnoses. Objective: The main aim of this study was to compare the concordance of the Idylla microsatellite instability test for the identification of dMMR endometrial cancer samples defined by immunohistochemistry and MMR genomic status. Design: We applied the Idylla MSI test to 126 early-stage endometrial cancer cases with MMR testing by immunohistochemistry and genomic characterization (methylation in MLH1 and sequence alterations in MLH1, PMS2, MSH2 and MSH6). Individual markers and overall specific performance indicators were explored. Results: The Idylla platform achieved a higher global concordance rate with MMR genomic status than with immunohistochemistry (75 % and 66 %, respectively). Sensitivity and specificity are also higher (75 % vs 66 % and 96 % vs 90 %, respectively). Clustering analysis split the patients into 2 well-differentiated clusters, the pMMR and the dMMR group, represented by MLH1/PMS2 loss and the MLH1 methylated promoter. Overall, immunohistochemistry and MMR genomic status identified more dMMR cases than did the Idylla test, although correlations were improved with a modified Idylla test cut-off. Conclusions: Performance of the Idylla test was better correlated with MMR genomic status than MMR immunohistochemistry status, which improved with a modified test cut-off. Further studies are needed to confirm the cut-off accuracy.